<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Vue3 测试实例1</title>
    <script src="https://lf3-cdn-tos.bytecdntp.com/cdn/expire-1-M/vue/3.2.31/vue.global.min.js"></script>
</head>
<body>
<div id="app" class="demo">

</div>
<script type="application/javascript">
    const app = Vue.createApp({
        data() {
            return {
                message: 'Hello Vue!'
            }
        }
    })
    var vm = app.mount('#app');

    document.write(vm.$data.count) // => 4
    document.write("<br>")
    document.write(vm.count)       // => 4
    document.write("<br>")
    // 修改 vm.count 的值也会更新 $data.count
    vm.$data.count = 5;
    document.write(vm.count);
</script>
</body>
</html>
